Speeding up or slowing down video and audio in Avisynth?

[Starks]

How would I go about increasing the tempo of video file (with audio) by very specific amounts (like +5%) in Avisynth without changing the pitch?

[tebasuna51]

To modify the audio duration preserving the pitch you can use:

TimeStretch(last, tempo = (100.0 * (actual_duration / desired_duration))